Increased risk of colorectal adenomas with metabolic-associated fatty liver disease components

BACKGROUND

Metabolic (dysfunction)-associated fatty liver disease is the most common liver disease related to various metabolic disorders. Colorectal adenomas are related to metabolic dysregulation. Despite the proposed association between non-alcoholic fatty liver disease and colorectal adenomas, the influence of metabolic-associated fatty liver disease on colorectal adenomas has yet to be investigated. Our study investigates the relationship between metabolic-associated fatty liver disease and colorectal adenomas and evaluates the predictive value of fatty liver index for colorectal adenomas.

METHODS

A retrospective cross-sectional study was conducted on 650 inpatients at Qinghai Provincial People's Hospital. All participants underwent colonoscopy, abdominal ultrasound or CT, relevant laboratory tests, and physical examinations to ascertain baseline characteristics and overall health status. Multivariate logistic regression analysis examined the relationship between metabolic-associated fatty liver disease and colorectal adenomas. Lastly, the ability to identify, accuracy, and clinical applicability of predicting colorectal adenomas through fatty liver index were assessed using receiver operating characteristic curve area under the curve, calibration curve, and decision curve analysis.

RESULT

In both the colorectal adenomas and control groups, the prevalence of metabolic-associated fatty liver disease was 62.1 % and 35.7 %, respectively. Multivariate analysis indicates that metabolic-associated fatty liver disease was independently correlated with an increased risk of colorectal adenomas (OR, 1.565; 95 % CI, 1.057-2.319; P < 0.05). Further analysis revealed that the risk of colorectal adenomas increased with an increasing quantity of metabolic components in metabolic-associated fatty liver disease (Ptrend < 0.001). The area under the curve of the fatty liver index predictive model was 0.838, with a 95 % CI of 0.807-0.869. The calibration curve indicated excellent agreement, and the decision curve analysis revealed a higher net benefit.

CONCLUSION

The risk of colorectal adenomas was associated with metabolic-associated fatty liver disease, and the risk of developing colorectal adenomas increased with the presence of more metabolic-associated fatty liver disease metabolic components. Furthermore, fatty liver index served as a predictive indicator for screening colorectal adenomas.

Differences in circulating lymphocyte subpopulations among patients with inflammatory polyps, colorectal adenomas and colorectal cancer

BACKGROUND AND STUDY AIMS

Colorectal cancer (CRC) may develop from focal changes within benign or precancerous polyps. The immune system's failure to detect and eradicate tumor cells due to immune surveillance evasion, allows cancer to develop and spread. This study aims to analyze the differences in circulating lymphocyte subpopulations in patients with colorectal inflammatory polyps, colorectal adenomas and CRC.

PATIENTS AND METHODS

We retrospectively reviewed patients from September 2016 to December 2019 at the Shaoxing Second Hospital. Using flow cytometry, the subset distribution and immunophenotype of T cells, CD4+ T cells, CD8+ T cells, B cells and NK cells were investigated in peripheral blood mononuclear cell samples. The counts of lymphocytes were determined by white blood cell counts.

RESULTS

In total, 518 patients were included in this study. The counts of lymphocytes, T cells and NK cells in patients with inflammatory polyps, colorectal adenomas and CRC were lower than controls. The counts and percentages of CD8+ T cells in patients with inflammatory polyps, colorectal adenomas and CRC were lower than controls. The counts of CD4+ T cells were lower in patients with CRC than inflammatory polyps. The percentages of CD4+ T cells in patients with inflammatory polyps, colorectal adenomas and CRC were higher than controls, but lower in the CRC than inflammatory polyps, colorectal adenomas. The counts and percentages of B cells were lower in CRC patients than colorectal adenomas patients. In addition, the percentages of B cells were higher in patients with inflammatory polyps and colorectal adenomas than in controls.

CONCLUSIONS

The decrease in counts of lymphocyte, T cells, CD8+ T cells and NK cells in patients may be related to the dysplasia of epithelial cells. Furthermore, the B cells and CD4+ T cells may be related to the malignant growth of the dysplastic epithelial cells.

Enrichment of colibactin-associated mutational signatures in unexplained colorectal polyposis patients

BACKGROUND

Colibactin, a genotoxin produced by polyketide synthase harboring (pks+) bacteria, induces double-strand breaks and chromosome aberrations. Consequently, enrichment of pks+Escherichia coli in colorectal cancer and polyposis suggests a possible carcinogenic effect in the large intestine. Additionally, specific colibactin-associated mutational signatures; SBS88 and ID18 in the Catalogue of Somatic Mutations in Cancer database, are detected in colorectal carcinomas. Previous research showed that a recurrent APC splice variant perfectly fits SBS88.

METHODS

In this study, we explore the presence of colibactin-associated signatures and fecal pks in an unexplained polyposis cohort. Somatic targeted Next-Generation Sequencing (NGS) was performed for 379 patients. Additionally, for a subset of 29 patients, metagenomics was performed on feces and mutational signature analyses using Whole-Genome Sequencing (WGS) on Formalin-Fixed Paraffin Embedded (FFPE) colorectal tissue blocks.

RESULTS

NGS showed somatic APC variants fitting SBS88 or ID18 in at least one colorectal adenoma or carcinoma in 29% of patients. Fecal metagenomic analyses revealed enriched presence of pks genes in patients with somatic variants fitting colibactin-associated signatures compared to patients without variants fitting colibactin-associated signatures. Also, mutational signature analyses showed enrichment of SBS88 and ID18 in patients with variants fitting these signatures in NGS compared to patients without.

CONCLUSIONS

These findings further support colibactins ability to mutagenize colorectal mucosa and contribute to the development of colorectal adenomas and carcinomas explaining a relevant part of patients with unexplained polyposis.

Is Metformin Associated with a Lower Prevalence of Polyps, Adenomas, and Colorectal Carcinoma in Patients with Diabetes Mellitus?

PURPOSE

Recent studies suggested a protective role of metformin in the development of colorectal cancer (CRC) and its precursors. We aimed to investigate if metformin was associated with a lower prevalence and number of colorectal polyps in diabetic patients and also adenomas, high-risk adenomas, and CRC.

METHODS

Retrospective study on adult patients with diabetes mellitus followed in our hospital with a total colonoscopy between 2015 and 2019, treated with either metformin for > 5 years or other antidiabetic agent (control group). We assessed the number, size, and histopathology examination of proliferative lesions detected on colonoscopy.

RESULTS

We included 401 patients aged 69 ± 9 years, 57% males, divided into two groups: treated with metformin (n = 260) and without (n = 141). The number of polyps detected was significantly lower in patients under metformin (p = 0.014). There was a nonsignificant trend towards lower polyp detection rates in the metformin compared to the control group both in unadjusted analysis (50% vs 60%, p = 0.058) and multivariable adjusted analysis (odds ratio [OR] 0.68, 95% confidence interval [CI] 0.43-1.09, p = 0.111). In the latter, we identified male gender (OR 2.24, 95%CI 1.44-3.49, p < 0.001), age (OR 1.35 for every 10 years, 95%CI 1.07-1.71, p = 0.012), glycated hemoglobin value (OR 1.20 for every 1% increase, 95%CI 1.06-1.37, p = 0.005), and hypertension (OR 1.76, 95%CI 1.01-3.08, p = 0.046) as factors associated with a higher prevalence of polyps. We saw no statistically significant differences regarding adenoma (p = 0.231), high-risk adenoma (p = 0.810), and CRC (p = 0.705) diagnoses between groups.

CONCLUSION

In our study, metformin was associated with less colorectal polyps in diabetic patients compared to other treatment modalities. We observed a nonsignificant trend towards lower polyp detection rates in the metformin group both in unadjusted and adjusted analyses.

Association of clinical characteristics and recurrence of conventional colorectal adenomas with patient age: a single-center study

OBJECTIVES

We performed a clinical study comparing early-onset and late-onset conventional colorectal adenomas (CCRAs) since little is known about the differences in their characteristics.

METHODS

Pearson's chi-square test and the Kruskal‒Wallis test were used to compare basic information. MCAR tests and multiple imputation were performed to complete missing values. Multivariate logistic analysis and propensity score matching were used to identify the risk factors for recurrence.

RESULTS

We included 2793 patients (688 with early-onset CCRAs and 2105 with late-onset CCRAs) from January 2017 to December 2021. Patients with early-onset CCRAs had higher levels of Hb, ALB, and triglycerides but lower HDL levels and N/L ratios. Moreover, we found that more early-onset CCRAs were in the left colon than late-onset CCRAs, and the size of early-onset CCRAs was larger. Early-onset CCRAs tended to lack pedicles compared to late-onset CCRAs. Additionally, the ratio of EMR and APC in early-onset CCRAs was higher than that in late-onset CCRAs, and the ratio of ESD and surgery for late-onset CCRAs was higher. We found that age ≥ 50 years, abnormal vessels, drinking alcohol, and DB and ALB levels may be risk factors for recurrence, while the LDL level may be a protective factor. Finally, analysis of cumulative recurrence rates after PSM showed that patients with late-onset CCRAs exhibited higher recurrence rates (P < 0.05).

CONCLUSION

Compared with late-onset CCRAs, early-onset CCRAs were associated with higher triglyceride levels, lower HDL levels, and larger tumor volumes. Age ≥ 50 years, abnormal vessels, alcohol consumption, and DB and ALB levels were independent risk factors for recurrence of CCRAs.

Berberine: An inspiring resource for the treatment of colorectal diseases

Colorectal cancer is a prevalent malignant tumor with a complex and diverse pathogenesis. In recent years, natural products have shown promising application prospects as sources of anticancer drugs. BBR, a class of benzoquinoline alkaloids extracted from various plants, is widely used in disease treatments owing to its pharmacological activities, including antibacterial, anti-inflammatory, antioxidant, anticancer, and anti-angiogenesis properties. Research has demonstrated that BBR exerts an anti-Salmonella and -Escherichia coli infection effect, attenuating inflammatory reactions by inhibiting harmful bacteria. During the stage of colorectal precancerous lesions, BBR inhibits the activity of cell cyclin by regulating the PI3K/AKT, MAPK, and Wnt signaling pathways, thereby decelerating the cell cycle progression of polyp or adenoma cells. Moreover, the inhibitory effect of BBR on colorectal cancer primarily occurs through the regulation of the cancer cell cycle, anti-angiogenesis, gut microbiota, and antioxidant pathways. The specific involved pathways include the MPK/ERK, NF-kB, and EGFR signaling pathways, encompassing the regulation of Bcl-2 family proteins, vascular endothelial growth factor, and superoxide dismutase. This study reviews and summarizes, for the first time, the specific mechanisms of action of BBR in the carcinogenesis process of colorectal cancer, providing novel insights for its clinical application in intestinal diseases.

Association of polymorphisms of calcium reabsorption genes SLC12A1, KCNJ1 and SLC8A1 with colorectal adenoma

BACKGROUND

In recent years, morbidity and mortality from colorectal cancer have increased. Colorectal adenoma is the main precancerous lesion. Understanding the pathogenesis of colorectal adenoma will help to improve the early diagnosis rate of colorectal cancer.

METHODS

In this case-control study, we focused on three single nucleotide polymorphisms (SNPs) in genes SLC8A1 (rs4952490), KCNJ1 (rs2855798), and SLC12A1 (rs1531916). We analyzed 207 colorectal adenoma patients (112 high-risk cases and 95 low-risk cases) and 212 control subjects by Sanger sequencing. A food frequency questionnaire (FFQ) was used to survey demographic characteristics and dietary nutrition.

RESULTS

In the overall analysis, the results suggested that the AA+AG and AG genotype carriers of rs4952490 had a 73.1% and 78% lower risk of colorectal adenoma compared to GG genotype carriers, respectively. However rs2855798 and rs1531916 were not associated with the incidence of colorectal adenoma. Additionally, stratified analysis showed that rs4952490 AA+AG and AG genotypes had a protective effect against low-risk colorectal adenoma in patients aged ≤ 60 years old who were non-smokers. We also observed that when calcium intake was higher than 616 mg/d and patients carried at least one gene with variant alleles there was a protective effect against low-risk colorectal adenoma.

CONCLUSIONS

Interactions between dietary calcium intake and calcium reabsorption genes may affect the occurrence and development of colorectal adenoma.

Endoscopic submucosal tunnel dissection vs conventional endoscopic submucosal dissection for large colorectal neoplasms: a single-centre retrospective study

BACKGROUND

Colorectal endoscopic submucosal dissection (ESD) is still not widely used due to its technical difficulty and the risk of complications. Several techniques, such as traction techniques, pocket techniques and others, have been proposed to facilitate it. One modified pocket technique especially suitable for large lesions is endoscopic submucosal tunnel dissection (ESTD). The aim of this study was to evaluate the safety and efficacy of ESTD and compare ESTD to the conventional ESD (CESD) for treating large colorectal lesions.

METHODS

The charts of consecutive patients referred to the Arcispedale Santa Maria Nuova (Reggio Emilia, Italy) for colorectal ESD between January 2014 and February 2021 for colorectal neoplasms > 40 mm were retrospectively analysed. The primary outcome of the study was the en bloc resection rate. Secondary outcomes were complete and curative resection rates, procedure speed, the adverse events rate and the recurrence rate.

RESULTS

There were 59 patients (M:F ratio 29:30, median age 70 years [range 50-93 years]). Of 59 colorectal lesions > 40 mm, 25 were removed by ESTD and 34 by CESD. The en bloc resection rate was 100% in both groups and the complete resection rate was similar (ESTD 92% vs CESD 97.1%, p = 0.569), while the curative resection rate was higher in the CESD group, but not significantly (94.1% vs 76%, p = 0.061). Procedure speed was significantly faster with ESTD (22 vs 17 mm²/min, p = 0.045), and the overall incidence of adverse events was low (6.8%). Eight patients were referred to surgery due to non-curative resection. During follow-up, no recurrence was observed in either treatment group.

CONCLUSION

ESTD achieves a very high en bloc resection rate and is faster than CESD.

The CHAMP-study: the CHemopreventive effect of lithium in familial AdenoMatous Polyposis; study protocol of a phase II trial

BACKGROUND

Familial adenomatous polyposis (FAP) is a rare autosomal dominant disease characterized by germline mutations in the Adenomatous Polyposis Coli (APC) gene, resulting in the development of numerous colorectal adenomas. As these patients have a high risk of developing colorectal cancer (CRC), guidelines suggest prophylactic colectomy during early adulthood, however, adenoma development is still observed in the remaining intestinal tract. Therefore, FAP patients would benefit from chemoprevention strategies reducing the development of adenomas. Recent work in mice reveals a chemopreventive effect of lithium on the development of adenomas by inhibiting the expansion of Apc mutated intestinal stem cells (ISCs) within the crypts of normal intestinal mucosa. Here, we aim to investigate the effect of lithium on the spread of APC mutant cells within the human intestinal epithelium.

METHODS

This prospective phase II single arm trial has a duration of 18 months. FAP patients (18-35 years) with a genetically confirmed APC mutation who did not undergo colectomy will be treated with lithium carbonate orally achieving a serum level of 0.2-0.4 mmol/l between month 6 and 12. Colonoscopy with biopsies of normal intestinal mucosa will be performed at baseline and every six months. The primary endpoint is the effect of lithium on the spread of APC mutant cells within intestinal crypts over time by using APC specific marker NOTUM in situ hybridization. Secondary endpoints include change in adenoma burden, patient reported side effects and safety-outcomes. Total sample size is 12 patients and recruitment will take place in the Amsterdam UMC, location AMC in the Netherlands.

DISCUSSION

The outcome of this study will function as a proof-of-concept for the development of novel chemoprevention approaches that interfere with the competition between normal and mutant ISCs.

TRIAL REGISTRATION

ClinicalTrials.gov ( https://clinicaltrials.gov/ ): NCT05402891 (June 1, 2022) and the EU Clinical Trials Register: EuraCT 2022-000240-30 (January 1, 2022).

Predictive Value of Genetic Risk Scores in the Development of Colorectal Adenomas

INTRODUCTION

Unlike colorectal cancer (CRC), few studies have explored the predictive value of genetic risk scores (GRS) in the development of colorectal adenomas (CRA), either alone or in combination with other demographic and clinical factors.

METHODS

In this study, genomic DNA from 613 Spanish Caucasian patients with CRA and 829 polyp-free individuals was genotyped for 88 single-nucleotide polymorphisms (SNPs) associated with CRC risk using the MassArray™ (Sequenom) platform. After applying a multivariate logistic regression model, five SNPs were selected to calculate the GRS. Regression models adjusted by sex, age, family history of CRC, chronic use of NSAIDs, low-dose ASA, and consumption of tobacco were built in order to study the association between GRS and CRA risk. We evaluated the discriminatory capacity using the area under the receiver operating characteristic curve (AUC). The interactions between demographic information and GRS were also analyzed.

RESULTS

Significant associations between high GRS values and risk of CRA for analyzed models were observed. In particular, patients with higher GRS values had 2.3-2.6-fold increase in risk of CRA compared to patients with middle values. Combining sex and age with the GRS significantly increased the discriminatory accuracy of the univariate model with GRS alone. The best model achieved an AUC value of 0.665 (95% CI: 0.63-0.69). The GRS showed a different behavior depending on sex and age.

CONCLUSION

Our findings showed that, besides sex and age, GRS is an important risk factor for development of CRA and may be useful for CRC risk stratification and adaptation of screening programs.

Texture and color enhancement imaging for detecting colorectal adenomas: Good, but not good enough

Texture and color enhancement imaging (TXI) has been developed as a novel image-enhancing endoscopy. However, the effectiveness of TXI detecting adenomas is inferior to narrow band imaging. Thus, future studies will need to focus on investigating the feasibility of such combination in clinical settings in order to provide patients with more accurate diagnoses.

Association of Helicobacter pylori enrichment in colorectal adenoma tissue on clinical and pathological features of adenoma

OBJECTIVE

To investigate the enrichment of Helicobacter pylori (Hp) in adenoma tissue of patients with colorectal adenoma, and analyze the correlation between the enrichment and the clinical and pathological characteristics of colorectal adenoma.

METHODS

The data of 1,622 patients undergoing gastrointestinal endoscopy in the Endoscopy Center of Wenzhou Integrated Traditional Chinese and Western Medicine Hospital affiliated to Zhejiang University of Traditional Chinese Medicine from January 2019 to June 2021 were retrospectively collected. The general data, gastric Hp infection, clinical and pathological features of colorectal adenoma, methylene blue staining of adenoma Hp, immunohistochemistry of adenoma Hp and immunofluorescence staining of adenoma TLR5 protein. were compared between the colorectal adenoma group (743 cases) and the control group (879 cases).

RESULTS

There were 361 gastric Hp positive cases in the colorectal adenoma group, with a positive rate of 48.59%, and 331 gastric Hp positive cases in the control group, with a positive rate of 37.66%, and the difference was statistically significant (P < 0.001). Gastric Hp infection significantly correlates with the Hp enrichment in colorectal adenomas (OR: 28.449; 95%CI: 18.188-44.500; P < 0.001). Moreover, we found that Hp enrichment in colorectal adenomas was correlated with the diameter, pathological type, and malignancy of adenoma (OR: 3.536; 3.652; 2.833; all P < 0.001). Expression TLR5 protein was also increased in Hp-enriched adenoma tissue.

CONCLUSION

There is a correlation between gastric Hp infection and intestinal Hp enrichment. The intestinal Hp enrichment significantly correlates with the clinical and pathological characteristics of colorectal adenomas, and its tumor-promoting effect may be related to the up-regulation of mucosal TLR5 expression.

Non-optical polyp-based resect and discard strategy: A prospective clinical study

BACKGROUND

Post-polypectomy surveillance intervals are currently determined based on pathology results.

AIM

To evaluate a polyp-based resect and discard model that assigns surveillance intervals based solely on polyp number and size.

METHODS

Patients undergoing elective colonoscopies at the Montreal University Medical Center were enrolled prospectively. The polyp-based strategy was used to assign the next surveillance interval using polyp size and number. Surveillance intervals were also assigned using optical diagnosis for small polyps (< 10 mm). The primary outcome was surveillance interval agreement between the polyp-based model, optical diagnosis, and the pathology-based reference standard using the 2020 United States Multi-Society Task Force guidelines. Secondary outcomes included the proportion of reduction in required histopathology evaluations and proportion of immediate post-colonoscopy recommendations provided to patients.

RESULTS

Of 944 patients (mean age 62.6 years, 49.3% male, 933 polyps) were enrolled. The surveillance interval agreement for the polyp-based strategy was 98.0% [95% confidence interval (CI): 0.97-0.99] compared with pathology-based assignment. Optical diagnosis-based intervals achieved 95.8% (95%CI: 0.94-0.97) agreement with pathology. When using the polyp-based strategy and optical diagnosis, the need for pathology assessment was reduced by 87.8% and 70.6%, respectively. The polyp-based strategy provided 93.7% of patients with immediate surveillance interval recommendations vs 76.1% for optical diagnosis.

CONCLUSION

The polyp-based strategy achieved almost perfect surveillance interval agreement compared with pathology-based assignments, significantly reduced the number of required pathology evaluations, and provided most patients with immediate surveillance interval recommendations.

Effects of Jianpi Lishi Jiedu granules on colorectal adenoma patients after endoscopic treatment: study protocol for a randomized, double-blinded, placebo-controlled clinical trial

BACKGROUND

Colorectal adenomas (CRAs) are precancerous lesions of the large intestine presenting as colorectal polyps. At present, the conventional treatment methods for CRA mainly include high-frequency electrocoagulation and electroexcision, biopsy forceps polypectomy, cauterization by laser and microwave, and other endoscopic interventions. The principal advantages conferred by these treatment strategies include less trauma, quick postoperative recovery, and simplicity to perform. However, the higher recurrence rates and insignificant improvement of postoperative symptoms after endoscopic surgery are considerable drawbacks to this approach. Besides, there is currently no effective pharmacotherapy to prevent the recurrence of CRA. Jianpi Lishi Jiedu (JLJ) granules are a form of traditional Chinese medicine (TCM) used to manage postoperative patients with CRA, which has shown a certain degree of efficacy in clinical practice. However, its effectiveness and safety profile have not been convincingly evaluated. The purpose of this study is to evaluate the clinical efficacy and safety profile of JLJ granules in the management of postoperative patients with CRA and to observe the recurrence rate of adenoma in these patients.

METHODS

A randomized, double-blind, and placebo-controlled clinical trial is performed in this study. A total of 80 postoperative patients with CRA will be randomly classified into the Jianpi Lishi Jiedu granules group or the placebo control group. Patients in both groups shall receive 3 months of intervention, after which medical follow-up and safety evaluation will be performed for all of the patients. The primary outcome is the recurrence rate of adenomas within 12 months. The secondary outcomes are the cardinal TCM symptom scores, minor TCM symptom scores, Bristol Stool Scale, efficacy of TCM symptoms, safety indicators, and blinding assessment.

DISCUSSION

In this study, the impact on the recurrence of adenomas and the efficacy and safety of JLJ granules in terms of improving the clinical symptoms of postoperative patients with CRA will be evaluated.

TRIAL REGISTRATION

Trial registration Chinese Clinical Trial Registry ChiCTR 2100044297. Registered on March 16, 2021.

Plasma metabolomic profiles for colorectal cancer precursors in women

How metabolome changes influence the early process of colorectal cancer (CRC) development remains unknown. We conducted a 1:2 matched nested case-control study to examine the associations of pre-diagnostic plasma metabolome (profiled using LC-MS) with risk of CRC precursors, including conventional adenomas (n = 586 vs. 1141) and serrated polyps (n = 509 vs. 993), in the Nurses' Health Study (NHS) and NHSII. Conditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI). We used the permutation-based Westfall and Young approach to account for multiple testing. Subgroup analyses were performed for advanced conventional adenomas (defined as at least one adenoma of ≥ 10 mm or with high-grade dysplasia, or tubulovillous or villous histology) and high-risk serrated polyps that were located in the proximal colon or with size of ≥ 10 mm. After multiple testing correction, among 207 metabolites, higher levels of C36:3 phosphatidylcholine (PC) plasmalogen were associated with lower risk of conventional adenomas, with the OR (95% CI) comparing the 90th to the 10th percentile of 0.62 (0.48-0.81); C54:8 triglyceride (TAG) was associated with higher risk of serrated polyps (OR = 1.79, 95% CI: 1.31-2.43), and phenylacetylglutamine (PAG) was associated with lower risk (OR = 0.57, 95% CI:0.43-0.77). PAG was also inversely associated with advanced adenomas (OR = 0.57, 95% CI: 0.36-0.89) and high-risk serrated polyps (OR = 0.54, 95% CI: 0.32-0.89), although the multiple testing-corrected p value was > 0.05. Our findings suggest potential roles of lipid metabolism and phenylacetylglutamine, a microbial metabolite, in the early stage of colorectal carcinogenesis, particularly for the serrated pathway.

Efficacy and safety of berberine in preventing recurrence of colorectal adenomas: A systematic review and meta-analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Berberine(BBR) is a kind of isoquinoline alkaloids extracted from the rhizomes of Coptis chinensis Franch., which was the main active ingredient. Accumulating evidence has shown that it has potential pharmacological effects in preventing the recurrence of colorectal adenomas.

AIM OF THE STUDY

The roles of BBR in the overall recurrence of colorectal adenoma have still not been assessed because of the limitations of the available data and the restriction of a single study. Therefore, we evaluated the effectiveness and safety of BBR in preventing the recurrence of colorectal adenomas through a systematic review and meta-analysis of available data.

MATERIALS AND METHODS

We searched four English databases (PubMed (MEDLINE), the Cochrane Central Register of Controlled Trials (CENTRAL), Embase and Web of Science) and four Chinese language databases (Chinese Biomedicine (CBM), China National Knowledge Infrastructure (CNKI), Chinese Scientific Journals Database (VIP) and the WanFang Database) from their inception through October 2020. Meta-analysis was performed with RevMan5.3 software after data extraction and the quality of studies assessment.

RESULTS

Three randomized controlled clinical trials were included with 1076 patients. Our results illustrated that 1-year and 2-year supplementation with BBR was associated with lower recurrence rate of colorectal adenoma (RR 0.69, 95% CI 0.57 to 0.84, p=0.0001; RR 0.75, 95% CI 0.64 to 0.88, p=0.0004). The relative risk of oral BBR for 1 year and 2 years is not comparable, for 2-year efficacy outcomes were assessed in all participants who had at least one colonoscopy with pathological evaluation after baseline (lots of participants completed the first colonoscopy but discontinued during the second follow-up interval.). Moreover, the results also suggest that BBR had more adverse events than placebo (RR 2.91, 95% CI 1.24 to 6.85, p=0.01). Through the full-text reading, no serious adverse events were observed, and constipation was the most common event which disappears once the drug is discontinued.

CONCLUSION

Generally, the present study indicated that BBR has a comparable therapeutic effect on the prevention of colorectal adenomas recurrence. Adverse reactions are worthy of attention which requires additional studies to obtain a precise conclusion.

PROSPERO REGISTRATION NO

CRD42020209135.

A case-control study of Dietary Approaches to Stop Hypertension (DASH) diets, colorectal cancer and adenomas among Iranian population

Background and aims

Colorectal cancer (CRC) is the third most common cancer, worldwide. Recently, much attention has been given to the association between Dietary Approaches to Stop Hypertension (DASH) and CRC, however, data on colorectal adenomas (CRAs) as its precursor are scarce. Thus, the purpose of this case-control study was to investigate the association of DASH score with the risk of CRC and CRA in Iranian adults.

Method

A total of 499 participants, including 129 CRC and 130 CRA cases, along with 240 controls, were asked about their dietary intake via a validated questionnaire. The DASH score was then calculated based on a priori methods and categorized in quartiles. Multivariate logistic regression was performed to assess the association of DASH score and the risk of CRC and CRA.

Results

After adjusting for confounding variables, adherence to the DASH diet was associated with a reduction in the risk of CRC and CRA, respectively (OR of 4th versus 1st quartile = 0.04, 95% CI: 0.01–0.11, OR = 0.10, 95% CI: 0.04–0.22). Also, subgroup analysis based on gender showed that women and men with a higher DASH score had a significantly lower risk of CRC and CRAs.

Conclusion

The results of this study demonstrated that adherence to a DASH dietary pattern could reduce the risk of CRC and CRA in men and women. Promoting a DASH eating plan can be helpful in reducing the risk of CRC.

Evaluation of global and intragenic hypomethylation in colorectal adenomas improves patient stratification and colorectal cancer risk prediction

Background

Aberrant DNA hypomethylation of the long interspersed nuclear elements (LINE-1 or L1) has been recognized as an early event of colorectal transformation. Simultaneous genetic and epigenetic analysis of colorectal adenomas may be an effective and rapid strategy to identify key biological features leading to accelerated colorectal tumorigenesis. In particular, global and/or intragenic LINE-1 hypomethylation of adenomas may represent a helpful tool for improving colorectal cancer (CRC) risk stratification of patients after surgical removal of polyps. To verify this hypothesis, we analyzed a cohort of 102 adenomas derived from 40 high-risk patients (who developed CRC in a post-polypectomy of at least one year) and 43 low-risk patients (who did not develop CRC in a post-polypectomy of at least 5 years) for their main pathological features, the presence of hotspot variants in driver oncogenes (KRAS, NRAS, BRAF and PIK3CA), global (LINE-1) and intragenic (L1-MET) methylation status.

Results

In addition to a significantly higher adenoma size and an older patients’ age, adenomas from high-risk patients were more hypomethylated than those from low-risk patients for both global and intragenic LINE-1 assays. DNA hypomethylation, measured by pyrosequencing, was independent from other parameters, including the presence of oncogenic hotspot variants detected by mass spectrometry. Combining LINE-1 and L1-MET analyses and profiling the samples according to the presence of at least one hypomethylated assay improved the discrimination between high and low risk lesions (p = 0.005). Remarkably, adenomas with at least one hypomethylated assay identified the patients with a significantly (p < 0.001) higher risk of developing CRC. Multivariable analysis and logistic regression evaluated by the ROC curves proved that methylation status was an independent variable improving cancer risk prediction (p = 0.02).

Conclusions

LINE-1 and L1-MET hypomethylation in colorectal adenomas are associated with a higher risk of developing CRC. DNA global and intragenic hypomethylation are independent markers that could be used in combination to successfully improve the stratification of patients who enter a colonoscopy surveillance program.

Graphic abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-021-01135-0.

Very-low-dose aspirin and surveillance colonoscopy is cost-effective in secondary prevention of colorectal cancer in individuals with advanced adenomas: network meta-analysis and cost-effectiveness analysis

BACKGROUND

Individuals with advanced colorectal adenomas (ACAs) are at high risk for colorectal cancer (CRC), and it is unclear which chemopreventive agent (CPA) is safe and cost-effective for secondary prevention. We aimed to determine, firstly, the most suitable CPA using network meta-analysis (NMA) and secondly, cost-effectiveness of CPA with or without surveillance colonoscopy (SC).

METHODS

Systematic review and NMA of randomised controlled trials were performed, and the most suitable CPA was chosen based on efficacy and the most favourable risk-benefit profile. The economic benefits of CPA alone, 3 yearly SC alone, and a combination of CPA and SC were determined using the cost-effectiveness analysis (CEA) in the Malaysian health-care perspective. Outcomes were reported as incremental cost-effectiveness ratios (ICERs) in 2018 US Dollars ($) per quality-adjusted life-year (QALY), and life-years (LYs) gained.

RESULTS

According to NMA, the risk-benefit profile favours the use of aspirin at very-low-dose (ASAVLD, ≤ 100 mg/day) for secondary prevention in individuals with previous ACAs. Celecoxib is the most effective CPA but the cardiovascular adverse events are of concern. According to CEA, the combination strategy (ASAVLD with 3-yearly SC) was cost-saving and dominates its competitors as the best buy option. The probability of being cost-effective for ASAVLD alone, 3-yearly SC alone, and combination strategy were 22%, 26%, and 53%, respectively. Extending the SC interval to five years in combination strategy was more cost-effective when compared to 3-yearly SC alone (ICER of $484/LY gain and $1875/QALY). However, extending to ten years in combination strategy was not cost-effective.

CONCLUSION

ASAVLD combined with 3-yearly SC in individuals with ACAs may be a cost-effective strategy for CRC prevention. An extension of SC intervals to five years can be considered in resource-limited countries.

Diet-dependent acid load and the risk of colorectal cancer and adenoma: a case-control study

OBJECTIVES

Colorectal cancer (CRC) is the third and second most prevalent cancer in men and women, respectively. Various epidemiological studies indicated that dietary factors are implicated in the aetiology of CRC and its precursor, colorectal adenomas (CRA). Recently, much attention has been given to the role of acid-base balance in the development of chronic diseases including cancers. Therefore, the aim of the current study is to examine the association of diet-dependent acid load and the risk of CRC and CRA.

DESIGN

In this case-control study, potential renal acid load (PRAL) was computed based on dietary intake of participants assessed via a validated FFQ. Negative PRAL values indicated a base-forming potential, while positive values of PRAL implied acid-forming potential of diet. Logistic regression was used to derive OR and 95 % CI after adjusting for confounders.

SETTING

Tehran, Iran.

PARTICIPANTS

A total of 499 participants aged 30-70 years were included in the study (240 hospital controls, 129 newly diagnosed CRC and 130 newly diagnosed CRA). The current study was conducted between December 2016 and September 2018.

RESULTS

After adjusting for potential confounders, a higher PRAL was associated with increased odds of CRC and CRA. The highest v. the lowest tertile of PRAL for CRC and CRA was OR 4·82 (95 % CI 2·51-9·25) and OR 2·47 (95 % CI 1·38-4·42), respectively.

CONCLUSIONS

The findings of the current study suggested that higher diet-dependent acid load is associated with higher risk of CRC and CRA.

Expression of Notch pathway components (Numb, Itch, and Siah-1) in colorectal tumors: A clinicopathological study

BACKGROUND

The role of the Notch pathway in carcinogenesis and tumor progression has been demonstrated in many organs, including the colon. Accordingly, studies aimed at developing therapies targeting this pathway in various cancers require the identification of several factors that may play a role in regulating Notch-1 expression. Although Numb, Itch, and seven in absentia homolog-1 (Siah-1) have been shown to contribute to the regulation of Notch signaling, their role in colorectal carcinogenesis and tumor progression has not been fully elucidated to date.

AIM

To evaluate Numb, Itch, and Siah-1 expression in colorectal tumors to clarify their relationship with Notch-1 expression and their role in carcinogenesis and tumor behavior.

METHODS

Expression of Notch-1, Numb, Itch, and Siah-1 was investigated in 50 colorectal carcinomas, 30 adenomas, and 20 healthy colonic tissues by immunohistochemistry and quantitative real-time polymerase chain reaction (PCR) analyses.

RESULTS

In contrast to Notch-1, which is expressed at higher levels in tumor tissues and adenomas, expression of Numb, Itch, and Siah-1 was stronger and more frequent in normal mucosa (P < 0.01). There was a positive correlation between Notch-1 expression and high histological grade, the presence of lymph node metastasis, and advanced-stage tumors, whereas expression of Numb, Itch, and Siah-1 was absent or reduced in tumors with these clinicopathological parameters (P < 0.05). In survival analysis, expression of Notch was related to poor prognosis but that of Numb, Itch, and Siah-1 correlated with improved survival (P < 0.05). Multivariate analysis revealed Notch-1 expression and loss of Numb expression to be independent prognostic parameters together with lymph node metastasis (P < 0.05).

CONCLUSION

Our findings support the role of Notch-1 in colorectal carcinoma and indicate that loss of Numb, Itch, and Siah-1 expression is associated with carcinogenesis. Our data also suggest that these three proteins might be involved in the Notch-1 pathway during colorectal carcinoma (CRC) progression and might play an essential role in approaches targeting Notch as novel molecular therapies for CRC.

The Case for High-Quality Colonoscopy Remaining a Premier Colorectal Cancer Screening Strategy in the United States

Most colorectal cancer screening in the United States occurs in the opportunistic setting, where screening is initiated by a patient-provider interaction. Colonoscopy provides the longest-interval protection, and high-quality colonoscopy is ideally suited to the opportunistic setting. Both detection and colonoscopic resection have improved as a result of intense scientific investigation. Further improvements in detection are expected with the introduction of artificial intelligence programs into colonoscopy platforms. We may expect recommended intervals or colonoscopy after negative examinations performed by high-quality detectors to expand beyond 10 years. Thus, high-quality colonoscopy remains an excellent approach to colorectal cancer screening in the opportunistic setting.

Colorectal cancer susceptibility variants and risk of conventional adenomas and serrated polyps: results from three cohort studies

BACKGROUND

Increasing evidence suggests that conventional adenomas (CAs) and serrated polyps (SPs) represent two distinct groups of precursor lesions for colorectal cancer (CRC). The influence of common genetic variants on risk of CAs and SPs remain largely unknown.

METHODS

Among 27 426 participants within three prospective cohort studies, we created a weighted genetic risk score (GRS) based on 40 CRC-related single nucleotide polymorphisms (SNPs) identified in previous genome-wide association studies; and we examined the association of GRS (per one standard deviation increment) with risk of CAs, SPs and synchronous CAs and SPs, by multivariable logistic regression. We also analysed individual variants in the secondary analysis.

RESULTS

During 18-20 years of follow-up, we documented 2952 CAs, 1585 SPs and 794 synchronous CAs and SPs. Higher GRS was associated with increased risk of CAs [odds ratio (OR) = 1.17, 95% confidence interval (CI): 1.12-1.21] and SPs (OR = 1.09, 95% CI: 1.03-1.14), with a stronger association for CAs than SPs (Pheterogeneity=0.01). An even stronger association was found for patients with synchronous CAs and SPs (OR = 1.32), advanced CAs (OR = 1.22) and multiple CAs (OR = 1.25). Different sets of variants were associated with CAs and SPs, with a Spearman correlation coefficient of 0.02 between the ORs associating the 40 SNPs with the two lesions. After correcting for multiple testing, three variants were associated with CAs (rs3802842, rs6983267 and rs7136702) and two with SPs (rs16892766 and rs4779584).

CONCLUSIONS

Common genetic variants play a potential role in the conventional and serrated pathways of CRC. Different sets of variants are identified for the two pathways, further supporting the aetiological heterogeneity of CRC.

The landscape of genomic copy number alterations in colorectal cancer and their consequences on gene expression levels and disease outcome

Aneuploidy, the unbalanced state of the chromosome content, represents a hallmark of most solid tumors, including colorectal cancer. Such aneuploidies result in tumor specific genomic imbalances, which emerge in premalignant precursor lesions. Moreover, increasing levels of chromosomal instability have been observed in adenocarcinomas and are maintained in distant metastases. A number of studies have systematically integrated copy number alterations with gene expression changes in primary carcinomas, cell lines, and experimental models of aneuploidy. In fact, chromosomal aneuploidies target a number of genes conferring a selective advantage for the metabolism of the cancer cell. Copy number alterations not only have a positive correlation with expression changes of the majority of genes on the altered genomic segment, but also have effects on the transcriptional levels of genes genome-wide. Finally, copy number alterations have been associated with disease outcome; nevertheless, the translational applicability in clinical practice requires further studies. Here, we (i) review the spectrum of genetic alterations that lead to colorectal cancer, (ii) describe the most frequent copy number alterations at different stages of colorectal carcinogenesis, (iii) exemplify their positive correlation with gene expression levels, and (iv) discuss copy number alterations that are potentially involved in disease outcome of individual patients.

The presence of bacteria varies between colorectal adenocarcinomas, precursor lesions and non-malignant tissue

BACKGROUND

A causal association has been suggested between certain bacteria and colorectal cancer (CRC). Only a few studies have, however, investigated the presence of these bacteria directly in colon tissue with conflicting results. It is thus uncertain which role they may have in prognosis and carcinogenesis of CRC.

METHODS

Formalin-fixed and paraffin-embedded (FFPE) colorectal tissue samples from patients diagnosed with colorectal cancer (CRC)(tumor and paired normal tissue, n = 99), adenomas (n = 96), or diverticular disease (n = 104) were tested for the presence and bacterial load of Streptococcus gallolyticus (S. gallolyticus), Fusobacterium nucleatum (F. nucleatum), and Bacteroides fragilis (B. fragilis) using quantitative PCR. A subsequent broader search was conducted on a subset of samples using 16S ribosomal RNA gene sequencing. Finally, to evaluate the prognostic value, the bacterial status was compared to patient outcome.

RESULTS

S. gallolyticus was not detected by qPCR in any of the investigated tissue samples and F. nucleatum and B. fragilis were found to be equally distributed in tumors, paired normal tissue, and diverticula, but significantly less present in adenomas compared to both tumors and diverticula. Neither, F. nucleatum nor B. fragilis status affected the five-year prognosis of the patients. The 16S rRNA gene sequencing data revealed that tumors were associated with the Prevotella genus while conversely adenomas and diverticula were associated with Acinetobacter genus.

CONCLUSION

These findings do not support a role of F. nucleatum or B. fragilis during colorectal beginning, while S. gallolyticus was not implicated in the colorectal tissue of a Danish population. A potential role of the bacterial genera Prevotella and Acinetobacter was indicated, and requires further investigations.

Association of TM6SF2 rs58542926 gene polymorphism with the risk of non-alcoholic fatty liver disease and colorectal adenoma in Chinese Han population

Background

Genetic factors affect the risk of non-alcoholic fatty liver disease (NAFLD) and colorectal adenoma (CRA) importantly. Transmembrane protein 6 superfamily member 2 (TM6SF2) rs58542926 is a significant genetic susceptibility site for NAFLD. The relationships of TM6SF2 rs58542926 with the risk of NAFLD and CRA in Chinese Han population were unclear. The aim of this study was to investigate the association of TM6SF2 rs58542926 with the risk of NAFLD and CRA, and the effect of CRA on TM6SF2 rs58542926 carried NAFLD patients.

Results

A total of 839 Chinese Han population were included in this retrospective study. TM6SF2 rs58542926 polymorphism was genotyped in B-type ultrasonography proven NAFLD patients with or without CRA, CRA patients and healthy controls, using polymerase chain reaction. Serum lipid profiles were determined using biochemical methods. Statistical analyses were performed using SPSS statistical software, version 16.0 for mac. There was a significant difference in the distribution of genotype and allele of TM6SF2 rs58542926 in NAFLD and NAFLD&CRA patients compared to controls. The CT + TT genotypes were tightly associated with the risk of NAFLD and NAFLD&CRA. TM6SF2 rs58542926 T allele promotes the abnormal regulation of lipids metabolism and liver injury in NAFLD patients and NAFLD&CRA patients. CRA aggravates the clinical performance of NAFLD in T allele carriers.

Conclusions

We demonstrated the significant association between TM6SF2 rs58542926 polymorphism and the risk of NAFLD and NAFLD&CRA in a Chinese Han population. The TM6SF2 rs58542926 T allele promotes the abnormal regulation of lipid profiles and liver injury in NAFLD patients, NAFLD&CRA patients, and overall subjects.

Endoscopic Full-Thickness Resection of Colorectal Lesions with the New FTRD System: Single-Center Experience

Background and Aims

Endoscopic full-thickness resection (EFTR) is an emerging technique for the treatment of various conditions for which classic endoscopic resection techniques have failed or were considered to be at high risk for perforation. The full-thickness resection device (FTRD) is an over-the-scope system which allows a single-step EFTR. The aim of our study is to describe our experience in EFTR of colorectal lesions using the FTRD.

Methods

Nine patients (10 colorectal lesions) were proposed for EFTR. Safety, R0 resection and endoscopic treatment success were evaluated.

Results

Reasons for referral included nonlifting adenomas (n = 4), nonlifting adenoma recurrence (n = 5), and submucosal lesion (n = 1). EFTR was technically successful in all patients. The mean duration of the procedure was 55 min. R0 resection was obtained in all patients. No major complications were detected. All lesions were successfully treated by the endoscopic technique and no patient was referred for surgery. In patients with available follow-up (n = 6), no recurrence was detected.

Conclusions

EFTR is a feasible, reasonable time-consuming, safe, and promising endoscopic resection technique.

Key Messages

FTRD is an additional tool for difficult-to-treat colorectal lesions.

Randomised controlled trial comparing modified Sano’s and narrow band imaging international colorectal endoscopic classifications for colorectal lesions

AIM

To assess the utility of modified Sano′s (MS) vs the narrow band imaging international colorectal endoscopic (NICE) classification in differentiating colorectal polyps.

METHODS

Patients undergoing colonoscopy between 2013 and 2015 were enrolled in this trial. Based on the MS or the NICE classifications, patients were randomised for real-time endoscopic diagnosis. This was followed by biopsies, endoscopic or surgical resection. The endoscopic diagnosis was then compared to the final (blinded) histopathology. The primary endpoint was the sensitivity (Sn), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) of differentiating neoplastic and non-neoplastic polyps (MS II/IIo / IIIa / IIIb vs I or NICE 1 vs 2/3). The secondary endpoints were “endoscopic resectability” (MS II/IIo/IIIa vs I/IIIb or NICE 2 vs 1/3), NPV for diminutive distal adenomas and prediction of post-polypectomy surveillance intervals.

RESULTS

A total of 348 patients were evaluated. The Sn, Sp, PPV and NPV in differentiating neoplastic polyps from non-neoplastic polyps were, 98.9%, 85.7%, 98.2% and 90.9% for MS; and 99.1%, 57.7%, 95.4% and 88.2% for NICE, respectively. The area under the receiver operating characteristic curve (AUC) for MS was 0.92 (95%CI: 0.86-0.98); and AUC for NICE was 0.78 (95%CI: 0.69, 0.88). The Sn, Sp, PPV and NPV in predicting “endoscopic resectability” were 98.9%, 86.1%, 97.8% and 92.5% for MS; and 98.6%, 66.7%, 94.7% and 88.9% for NICE, respectively. The AUC for MS was 0.92 (95%CI: 0.87-0.98); and the AUC for NICE was 0.83 (95%CI: 0.75-0.90). The AUC values were statistically different for both comparisons (P = 0.0165 and P = 0.0420, respectively). The accuracy for diagnosis of sessile serrated adenoma/polyp (SSA/P) with high confidence utilizing MS classification was 93.2%. The differentiation of SSA/P from other lesions achieved Sp, Sn, PPV and NPV of 87.2%, 91.5%, 89.6% and 98.6%, respectively. The NPV for predicting adenomas in diminutive rectosigmoid polyps (n = 150) was 96.6% and 95% with MS and NICE respectively. The calculated accuracy of post-polypectomy surveillance for MS group was 98.2% (167 out of 170) and for NICE group was 92.1% (139 out of 151).

CONCLUSION

The MS classification outperformed the NICE classification in differentiating neoplastic polyps and predicting endoscopic resectability. Both classifications met ASGE PIVI thresholds.

Impact of Hyoscine Bromide Use on Polyp Detection Rate During Colonoscopy: A Systematic Review and Meta-Analysis

Background

Colorectal cancer (CRC) is a leading cause of death worldwide. Polyp detection rate (PDR) and adenoma detection rate (ADR) are key focus in endoscopic research for CRC screening and prevention. Use of anti-spasmodic agents during colonoscopy to help identify adenomas and polyps has remained a controversial topic. Hyoscine butyl bromide (HBB) is the most commonly used anti-spasmodic agent in patients undergoing colonoscopy. Some randomized controlled trials (RCTs) have questioned the clinical efficacy and safety of routine use of HBB for polyp and adenoma detection rates.

Methods

We conducted a systematic search in PubMed and MEDLINE from inception until February 10, 2018, for studies which compared HBB with placebo. We used RevMan version 5.3 for analysis. Procedural end-points were polyps, adenomas, and advanced adenoma detection rates, mean number of polyps detected and cecal intubation time.

Results

We included seven RCTs with 2,588 patients in our analysis. A total of 1,301 patients were randomized to HBB arm and 1,287 to the placebo arm. There was no significant difference in the primary outcome of polyp detection rate, 654 in HBB group vs. 616 in the placebo group, (odds ratio (OR) = 1.11, confidence interval (CI) = 0.93 - 1.34, P = 0.25). There was no difference in secondary outcomes of adenoma detection rate, 430 in HBB group vs. 396 in the placebo group, (OR = 1.06, CI = 0.89 - 1.26, P = 0.51), advanced adenoma detection rate, 92 in HBB vs. 95 in placebo group (OR = 0.95, CI = 0.70 - 1.30, P = 0.76), mean number of polyps detected (point estimate = 0.12, CI = 0.00 - 0.23, P = 0.05), adenomatous polyps (OR = 0.84, CI = 0.39 - 1.81, P = 0.65) and cecal intubation time (point estimate = 0.73, CI = -1.98 - 0.52, P = 0.25) between the two groups.

Conclusions

The use of HBB in patients undergoing colonoscopy does not appear to improve polyp or adenoma detection rates. It showed a non-significant trend of increased mean number of polyps detected with HBB.

Adenomas - Genetic factors in colorectal cancer prevention

Colorectal cancer is the second most common type of cancer both in Europe and Poland. During the last 30 years more than a 3-fold increase has been observed in Poland due to environmental and genetic factors. Almost all colorectal malignancies are related to the formation and malignant transformation of colorectal dysplasia and adenoma. Efforts aiming to decrease the number of colorectal cancer deaths are focused on the disease early detection. Genetic diagnosis for hereditary syndromes predisposing to colorectal cancer has been developed and is a part of the routine treatment. Most cancers are sporadic. They often develop from polyps in the colon. In addition to the genetic events described in the 1990s, showing the adenoma transformation into carcinoma that has been a prime example of malignant transformation for a long time, there are also other possibilities of neoplastic transformation. The recognition of colorectal cancer risk factors make sense as their nature is lifestyle- and diet-related. In this review paper those risk factors are presented and the prevention of colorectal cancer is discussed taking into account genetic factors.

Effects of aspirin and non-aspirin nonsteroidal anti-inflammatory drugs on the incidence of recurrent colorectal adenomas: a systematic review with meta-analysis and trial sequential analysis of randomized clinical trials

BACKGROUND

Beneficial effects of aspirin and non-aspirin nonsteroidal anti-inflammatory drugs (NSAIDs) against recurrent colorectal adenomas have been documented in systematic reviews; however, the results have not been conclusive. Uncertainty remains about the appropriate dose of aspirin for adenoma prevention. The persistence of the protective effect of NSAIDs against recurrent adenomas after treatment cessation is yet to be established.

METHODS

Our objective was to update and systematically evaluate the evidence for aspirin and other NSAIDs on the incidence of recurrent colorectal adenomas taking into consideration the risks of random error and to appraise the quality of evidence using GRADE (The Grading of Recommendations, Assessment, Development and Evaluation) approach. Retrieved trials were evaluated using Cochrane risk of bias instrument. Meta-analytic estimates were calculated with random-effects model and random errors were evaluated with trial sequential analysis (TSA).

RESULTS

In patients with a previous history of colorectal cancer or adenomas, low-dose aspirin (80-160 mg/day) compared to placebo taken for 2 to 4 years reduces the risk of recurrent colorectal adenomas (relative risk (RR), 0.80 [95% CI (confidence interval), 0.70-0.92]). TSA indicated a firm evidence for this beneficial effect. The evidence indicated moderate GRADE quality. Low-dose aspirin also reduces the recurrence of advanced adenomas (RR, 0.66 [95% CI, 0.44-0.99]); however, TSA indicated lack of firm evidence for a beneficial effect. High-dose aspirin (300-325 mg/day) did not statistically reduce the recurrent adenomas (RR, 0.90 [95% CI, 0.68-1.18]). Cyclooxygenase-2 (COX-2) inhibitors (e.g. celecoxib 400 mg/day) were associated with a significant decrease in the recurrence of both adenomas (RR, 0.66 [95% CI, 0.59-0.72]) and advanced adenomas (RR, 0.45 [95% CI, 0.33-0.57]); however, this association did not persist and there was a trend of an increased risk of recurrent adenomas observed 2 years after the withdrawal.

CONCLUSION

Our findings confirm the beneficial effect of low-dose aspirin on recurrence of any adenomas; however, effect on advanced adenomas was inconclusive. COX-2 inhibitors seem to be more effective in preventing recurrence of adenomas; however, there was a trend of an increased risk of recurrence of adenomas observed after discontinuing regular use.

Alcohol, smoking and the risk of premalignant and malignant colorectal neoplasms

Colorectal cancer (CRC) is the third most common cancer worldwide and has a complex aetiology consisting of environmental and genetic factors. In this review, we evaluate the roles of alcohol and tobacco smoking in colorectal neoplasia. Alcohol intake and tobacco smoking are associated with modest, but significantly, increased risks of CRC, adenomatous and serrated polyps. There is consistent evidence of dose-response relationships for both alcohol and smoking, and risk of these neoplasms. Alcohol and smoking appear to be more strongly associated with colorectal polyp than CRC development, suggesting roles in the initiation of neoplastic growths. These lifestyle factors also seem more strongly related to adenomas and sessile serrated lesions than hyperplastic polyps, but further confirmation is required. The gastroenterology community has an important, yet currently underexploited, role to play addressing the modifiable factors associated with CRC and polyps. These behaviours include, but are not limited to, alcohol and smoking.

Distribution of colorectal polyps: Implications for screening

BACKGROUND

During the last decades data from different studies reported modifications of the topographic distribution of colorectal cancers (CRCs), with an increased frequency of tumours in proximal colonic segments. Given the documented link between adenomas and CRC, a proximal migration of adenomas over time could be expected as well.

AIM

To evaluate available evidence about the prevalence of adenomas and of sessile serrated polyps across colonic segments, the changing trends in their distribution across the colon and the diagnostic performance of screening tests currently adopted in population based screening programs for lesions located in different colonic segments.

METHODS

Literature search on PubMed, Embase, and Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects with reference to preferred reporting items for systematic reviews and meta-analysis (PRISMA), considering all adult human studies in English, published between January 2000 and February 2017.

RESULTS

Cross-sectional analysis of endoscopy and pathology data-bases are consistently showing a trend toward an increase with age of the proportion of adenomas located in the proximal colon. Several observational studies analysed the site distribution of adenomas, testing the hypothesis of a proximal shift of these lesions, and most of them reported an increase in the proportion of right-sided adenomas over time, although a similar trend was not confirmed by others. Also the quality of the retrieved evidence was low. Both endoscopy and FIT are showing a different level of sensitivity for lesions arising in different colonic segments, depending also on screenees characteristics.

CONCLUSION

Available evidence is supporting the hypothesis of an increase in the proportion of right-sided adenomas with age, while a similar increase has not been reported for SSP/A, at least among subjects aged 50 or older. The trend toward a proximalization of colorectal adenomas over time, reported by some authors, likely results from improved diagnostic performances and/or the process of population ageing.

Functional Genomic mRNA Profiling of Colorectal Adenomas: Identification and in vivo Validation of CD44 and Splice Variant CD44v6 as Molecular Imaging Targets

Colorectal cancer (CRC) is the third leading cause of cancer-related deaths worldwide. High adenoma miss rates, especially seen in high-risk patients, demand for better endoscopic detection. By fluorescently 'highlighting' specific molecular characteristics, endoscopic molecular imaging has great potential to fulfill this need. To implement this technique effectively, target proteins that distinguish adenomas from normal tissue must be identified. In this study we applied in silico Functional Genomic mRNA (FGmRNA) profiling, which is a recently developed method that results in an enhanced view on the downstream effects of genomic alterations occurring in adenomas on gene expression levels. FGmRNA profiles of sporadic adenomas were compared to normal colon tissue to identify overexpressed genes. We validated the protein expression of the top identified genes, AXIN2, CEMIP, CD44 and JUN, in sporadic adenoma patient samples via immunohistochemistry (IHC). CD44 was identified as the most attractive target protein for imaging purposes and we proved its relevance in high-risk patients by demonstrating CD44 protein overexpression in Lynch lesions. Subsequently, we show that the epithelial splice variant CD44V6 is highly overexpressed in our patient samples and we demonstrated the feasibility of visualizing adenomas in Apc^Min/+ mice in vivo by using a fluorescently labeled CD44v6 targeting peptide. In conclusion, via in silico functional genomics and ex vivo protein validation, this study identified CD44 as an attractive molecular target for both sporadic and high-risk Lynch adenomas, and demonstrates the in vivo applicability of a small peptide drug directed against splice variant CD44v6 for adenoma imaging.

Safety of endoscopic mucosal resection (EMR) of large non-pedunculated colorectal adenomas in the elderly

BACKGROUND

Endoscopic mucosal resection (EMR) has been proven to be safe and effective for the treatment of colorectal adenomas. However, data are limited on the safety of this technique for large polyps and in elderly patients. Aims of our study were to examine the bleeding and perforation rates in patients with large non-pedunculated adenomas (≥20mm) and to evaluate the influence of size (≥40mm) and age (≥75 years) on the complication rates.

METHODS

In this multicenter retrospective study, patients who underwent EMR of non-pedunculated adenomas ≥20mm between January 2012 and March 2016 were included. The demographics of the patients, the use of antithrombotic drugs, size of the polyps, type of resection, pathology report, occurrence of post-polypectomy bleeding, and perforation- and recurrence rate were collected.

RESULTS

In 343 patients, 412 adenomas were removed. Eighty patients (23.3%) were ≥75 years of age, 138 polyps (33.5%) were ≥40mm. Bleeding complications were observed in 28 cases (6.8%) and were found significantly more frequent in adenomas ≥40mm, independent of the use of antithrombotic therapy. Five perforations (1.2%) were described, not related to the size of the polyp. There was no significant difference in complication rates between patients <75 years and patients ≥75 years. Bleeding complications rates were significantly higher in patients receiving double antithrombotic therapy.

CONCLUSION

EMR is safe in elderly patients. EMR of adenomas of ≥40mm was associated with more bleeding complications. Future studies should address how the bleeding rates can be reduced in these patients, especially in those who use double antithrombotic treatment.

A Review of Outcomes for Colorectal Adenomas

OBJECTIVES

Using data from former reports, this study reviews and analyzes the outcomes of tumor recurrence, tumor progression, and tumor-specific survival of patients with colorectal adenomas.

METHODS

Data were collected from 32 longitudinal studies of outcomes after the first diagnosis of colorectal adenoma and collected as individual patient results, that is, as failure times from the first tumor to the three outcomes. Altogether, there were 45,286 patients, including 22,148 for the outcome of additional adenomas, 23,796 for the outcome of progression to invasive carcinoma, and 2,602 for the outcome of disease-specific survival (some patients were available for more than one outcome).

RESULTS

In these data, the mean time to additional adenomas was 6 years, the mean time to invasive carcinoma was 15.9 years, and the mean tumor-specific survival time was 21.9 years.

CONCLUSIONS

Although greater than 50% of those with colorectal adenomas will have additional adenomas, few progress to invasive tumor or die of colorectal cancer.

Significance of plasma levels of adiponectin and leptin in elderly patients with colorectal adenomas and non-alcoholic fatty liver disease

AIM: To investigate the clinical characters of colorectal adenomas in elder patients with non-alcoholic fatty liver disease (NAFLD), and to explore the relationship between adiponectin and leptin levels and colorectal adenomas which likely undergo malignant transformation.

METHODS: The information of past medical history and personal medical history were provided. Body mass index (BMI), aspartate aminotransferase (AST), alanine aminotransferase (ALT), triglyceride (TG), total cholesterol (TC), high-density lipoprotein (HDL-C), low-density lipoprotein (LDL-C), lipoprotein a (Lpa), as well as position, size, number, and pathology of colorectal adenomas were detected and collected statistic between elderly patients with and without NAFLD. ELISA was used to detect plasma adiponectin and leptin levels.

RESULTS: More elderly patients with NAFLD had smoking history, diabetes mellitus, hypertension, hypertriglyceride, high LDL-C level and high BMI (P < 0.05) than in those without NAFLD. The numbers of colorectal adenomas (P < 0.05) and villous adenomas (P < 0.05) in patients with NAFLD were more than those in patients without NAFLD. Higher levels of adiponectin and lower levels of leptin were detected in patients with NAFLD, and in the villous adenomas group and high grade dysplasia group.

CONCLUSION: Adenomas in elderly patients with NAFLD have more chances to undergo malignant transformation than those in patients without NAFLD. The low expression of adiponectin and high expression of leptin may be one of the possible mechanisms.

Race and Prevalence of Large Bowel Polyps Among the Low-Income and Uninsured in South Carolina

BACKGROUND

Compared to whites, blacks have higher colorectal cancer incidence and mortality rates and are at greater risk for early-onset disease. The reasons for this racial disparity are poorly understood, but one contributing factor could be differences in access to high-quality screening and medical care.

AIMS

The present study was carried out to assess whether a racial difference in prevalence of large bowel polyps persists within a poor and uninsured population (n = 233, 124 blacks, 91 whites, 18 other) undergoing screening colonoscopy.

METHODS

Eligible patients were uninsured, asymptomatic, had no personal history of colorectal neoplasia, and were between the ages 45-64 years (blacks) or 50-64 years (whites, other). We examined the prevalence of any adenoma (conventional, serrated) and then difference in adenoma/polyp type by race and age categories.

RESULTS

Prevalence for ≥1 adenoma was 37 % (95 % CI 31-43 %) for all races combined and 36 % in blacks <50 years, 38 % in blacks ≥50 years, and 35 % in whites. When stratified by race, blacks had a higher prevalence of large conventional proximal neoplasia (8 %) compared to whites (2 %) (p value = 0.06) but a lower prevalence of any serrated-like (blacks 18 %, whites 32 %; p value = 0.02) and sessile serrated adenomas/polyps (blacks 2 %, whites 8 % Chi-square p value; p = 0.05).

CONCLUSIONS

Within this uninsured population, the overall prevalence of adenomas was high and nearly equal by race, but the racial differences observed between serrated and conventional polyp types emphasize the importance of taking polyp type into account in future research on this topic.

Hyperinsulinemia, insulin resistance and colorectal adenomas: A meta-analysis

BACKGROUND

Insulin stimulates cell proliferation and inhibits apoptosis. While epidemiologic studies have investigated associations between markers of insulin resistance/hyperinsulinemia (i.e., circulating insulin, homeostasis model assessment-insulin resistance (HOMA-IR), C-peptide) and risk of colorectal adenoma (CRA), the effect size has not yet been quantified.

OBJECTIVE

We aimed to summarize the association between hyperinsulinemia/insulin resistance and risk of CRA, including whether the association is independent of adiposity.

MATERIALS AND METHODS

Pubmed and Embase were searched through April, 2015 to identify observational studies investigating the associations between insulin, C-peptide and HOMA-IR and CRA risk. Using the highest versus lowest category meta-analysis and dose-response meta-analysis based on a random-effects model, we estimated summary odds ratio (OR) and the corresponding 95% confidence interval (95% CI).

RESULTS

A total of 27 studies (insulin: 16 studies including 14,007 cases; C-peptide: 11 studies including 8639 cases; HOMA-IR: 8 studies including 11,619 cases) were included in this meta-analysis. The summary ORs of CRA comparing the highest with the lowest quantile were 1.33 for insulin (95% CI=1.12-1.58, I(2)=73.9%, Pheterogeneity<0.001), 1.44 for C-peptide (95% CI=1.13-1.83, I(2)=63.5%, Pheterogeneity=0.003), and 1.33 for HOMA-IR (95% CI=1.10-1.60, I(2)=69.1%, Pheterogeneity=0.004). Upon stratification by ethnicity, higher levels of insulin and C-peptide were significantly associated with increased risk of CRA in non-Asian ethnicity (summary OR for insulin=1.67 [95% CI=1.28-2.17], I(2)=34.9%, Pheterogeneity=0.16; summary OR for C-peptide=1.59 [95% CI=1.22-2.08], I(2)=21.5%, Pheterogeneity=0.27) but not in Asians (summary OR for insulin=1.10 [95% CI=0.92-1.33], I(2)=76.6%, Pheterogeneity=0.001; summary OR for C-peptide=1.27 [95% CI=0.84-1.91], I(2)=72.6, Pheterogeneity=0.01). We observed evidence for the existence of publication bias for insulin (P=0.01 by Egger test) and HOMA-IR (P=0.05 by Egger test). The results were confirmed in linear dose-response meta-analysis. These significant positive associations generally persisted even after adjustment for adiposity, although the effect size was substantially attenuated.

CONCLUSIONS

Independent of adiposity, higher levels of insulin, C-peptide, and HOMA-IR were significantly associated with increased risk of CRA. The weaker associations and high heterogeneity in Asian studies warrant further research. These results indicate that insulin resistance and hyperinsulinemia may contribute in part to the association between obesity and CRA risk.

Predictors of guideline concordance for surveillance colonoscopy recommendations in patients at a safety-net health system

PURPOSE

Appropriate surveillance intervals for colorectal cancer (CRC) screening is one of the Centers for Medicare and Medicaid Services 2014 physician quality reporting system measures. Appropriateness of surveillance intervals will continue to be monitored closely, particularly as reimbursements become tied to quality measures.

AIMS

Quantify and identify predictors for guideline-concordant surveillance recommendations after adenoma polypectomy.

METHODS

We conducted a retrospective cohort study of patients who had colonoscopy with polypectomy at a safety-net health system between June 2011 and December 2013. Surveillance recommendations shorter and longer than guideline recommendations were defined as potential overuse and underuse. We used multivariate logistic regression to identify correlates of guideline-concordant surveillance recommendations, overuse, and underuse.

RESULTS

Among 1,822 patients with polypectomy, 1,329 had ≥1 adenoma. Surveillance interval recommendations were guideline-concordant in 1,410 (77.4%) patients, potential overuse in 263 (14.4%), potential underuse in 85 (4.7%), and missing in 64 (3.5%) patients. Predictors of guideline-concordant recommendations in multivariate analyses included age >65 years (OR 1.36, 95% CI 1.02-1.80), incomplete resection (OR 3.58, 95% CI 1.41-9.09), and good/excellent prep quality (OR 2.22, 95% CI 1.72-2.86). Underuse recommendations were more likely in patients with ≥3 adenomas; overuse recommendations were more likely in patients with high-grade dysplasia or fair prep quality and less likely in those with piecemeal resection, ≥3 adenomas, age >65, or Hispanic ethnicity.

CONCLUSIONS

Surveillance recommendations are not concordant with guidelines in one of four cases. Interventions to improve prep quality and guideline concordance of surveillance recommendations can improve cost-effectiveness of CRC screening.

Two Phenotypes of Traditional Serrated Adenomas Nationwide Survey in Iceland

Iceland has a total population of 300,000 inhabitants. All patients consulting for symptoms of the lower digestive tract during a four-year period (2003-2006) were subjected to a colonoscopic examination; all polyps were endoscopically removed. Out of the total 3,037 colorectal adenomas (CRAs), 308 (10.2%) were traditional serrated adenomas (TSAs). TSAs were divided according the predominant histological phenotype (>50%) into those with ectopic crypt formations (ECF), and those with unlocked serrations (US). ECF-TSA accounted for 5.9% (178/3037) and US-TSA for 4.3% (130/3037). The majority of patients with ECF-TSA and US-TSA were ≥ 60 years of age (74.1% and 76.2%, respectively). Notwithstanding, when patients having advanced adenomas (with high-grade dysplasia, with or without intramucosal carcinoma) were listed by age, those with ECF-TSA were significantly younger than those with US-TSA (p<0.05). ECF-TSA were more frequently left-sided (71.8%), whereas US-TSA were more frequently right-sided (60.0%). Invasive carcinoma evolved more frequently in ECF-TSA (7.8%) and in US-TSA (7.7%) than in tubular adenomas and in villous/tubulovillous adenomas (0.1% and 4.4%, respectively). Comparative studies indicated that the incidence rates/year of ECF-TSA and US-TSA were significantly higher in Iceland than in Sweden or in Italy (p<0.05). Genetic and putative epigenetic (environmental) factor(s) might account for the high incidence rate/year of ECF-TSA and US-TSA in this country.

Metabolic syndrome and colorectal neoplasms: An ominous association

AIM: To evaluate the association of metabolic syndrome (MS) and colorectal cancer and adenomas in a Western country, where the incidence of MS is over 27%.

METHODS: This was a prospective study between March 2013 and March 2014. MS was diagnosed according to the National Cholesterol Education Program-ATP III. Demographic characteristics, anthropometric measurements, metabolic risk factors, and colonoscopic pathologic findings were assessed in patients with MS (group 1) who underwent routine colonoscopy at our department. This data was compared with consecutive patients without metabolic syndrome (group 2), with no differences regarding sex and age. Patients with incomplete colonoscopy, family history, or past history of colorectal neoplasm were excluded. Informed consent was obtained and the ethics committee approved this study. Statistical analysis was performed using Student’s t-test and χ² test, with a P value ≤ 0.05 being considered statistically significant.

RESULTS: Of 258 patients, 129 had MS; 51% males; mean-age 67.1 years (50-87). Among the MS group, 94% had high blood pressure, 91% had increased waist circumference, 60% had diabetes, 55% had low high-density lipoprotein cholesterol level, 50% had increased triglyceride level, and 54% were obese [body mass index (BMI) 30 kg/m²]. 51% presented 4 criteria of MS. MS was associated with increased prevalence of adenomas (43% vs 25%, P = 0.004) and colorectal cancer (13% vs 5%, P = 0.027), compared with patients without MS. MS was also positively associated with multiple (≥ 3) adenomas (35% vs 9%, P = 0.024) and sessile adenomas (69% vs 53%, P = 0.05). No difference existed between location (P = 0.086), grade of dysplasia (P = 0.196), or size (P = 0.841) of adenomas. In addition, no difference was found between BMI (P = 0.078), smoking (P = 0.146), alcohol consumption (P = 0.231), and the presence of adenomas.

CONCLUSION: MS is positively associated with adenomas and colorectal cancer. However, there is not enough information in western European countries to justify screening in patients with MS. To our knowledge, no previous study has evaluated this association in Portuguese patients.

Type 2 diabetes mellitus and colorectal neoplasia risk in Hispanics: a case-control study

AIMS

There is inconclusive evidence regarding the potential link between diabetes mellitus (DM) and colorectal cancer (CRC). Associations between type 2 DM and colorectal neoplasia (CRN; colorectal cancer and/or adenomas) have not been well studied in Hispanics, an ethnic minority at high risk for type 2 DM. This study aims to assess the association between type 2 DM and CRN in Hispanics.

METHODS

Hispanics with incident CRN and colonoscopy-negative controls from 2005 to 2009 were evaluated. Diagnosis of type 2 DM was established by previous medical diagnosis and/or use of DM treatments. Unconditional logistic regression was performed to estimate odds ratios for the association between type 2 DM and CRN.

RESULTS

A total of 451 participants (mean age 61.1±11.9years, 59.6 % men) were evaluated (218 with incident CRC, 77 with colorectal adenomas, and 156 colonoscopy-negative controls). The prevalence of type 2 DM in this study was 25.1%. After adjusting for potential confounding variables, women with type 2 DM were 2.74 (95% CI: 0.94-7.99) times more likely to have CRN and 4.83 times more likely to present with proximal colonic CRN (95% CI: 1.25-18.58) than women without type 2 DM. No statistically significant associations were found between type 2 DM and CRN among men.

CONCLUSIONS

An increased odds for CRN and proximal location of CRN was observed among Hispanic women with type 2 DM. Since DM is a highly prevalent disease in this population, adherence to routine CRC screening is of outmost importance.

The efficacy and safety of non-steroidal anti-inflammatory drugs in preventing the recurrence of colorectal adenoma: a meta-analysis and systematic review of randomized trials

AIM

We report a meta-analysis and systematic review of randomized trials assessing the impact of non-steroidal anti-inflammatory drugs (NSAIDs) in preventing recurrence of colorectal adenoma.

METHOD

PubMed/Medicine, EMBASE and the Cochrane Central Register of Controlled Trials databases were searched for relevant randomized double-blind placebo-controlled trials published before March 2014. Two authors independently assessed study quality and extracted data. stata software was used to investigate heterogeneity between studies, and analysis was performed using a fixed-effects model to calculate and merge data.

RESULTS

Nine studies, with 8521 subjects, were included. Results were categorized by the duration of follow-up. The relative risks of any recurrence of adenoma in patients receiving NSAIDs compared with the placebo group were 0.68 [95% confidence interval (CI) 0.63-0.73, P = 0.001] for patients with a 1-year follow-up, 0.75 (95% CI 0.68-0.83, P = 0.246) with 3 years and 1.43 (95% CI 1.14-1.79, P = 0.127) with follow-up of over 3 years. Using pooled risk ratios, NSAIDs were associated with a significant decrease in adenoma recurrence at 1 and 3 years, although this association was lost beyond 3 years of follow-up. For secondary prevention of advanced adenomas, the pooled risk ratios (compared with placebo) were 0.51 (95% CI 0.43-0.60, P = 0.026) after 1 year, 0.61 (95% CI 0.50-0.76, P = 0.887) at 3 years and 1.39 (95% CI 0.89-2.16, P = 0.829) after 3 years.

CONCLUSION

The meta-analysis indicated that oral NSAIDs may be effective in the early prevention of secondary occurrence of adenomas.

p53 up-regulation during colorectal carcinogenesis

BACKGROUND

We previously found foci of p53 up-regulation in dysplasia in colorectal adenomas (CRAs). The present study aimed at exploring the frequency of this phenomenon in CRAs with and without submucosal invasive carcinoma.

MATERIALS AND METHODS

Sections from 568 polypectomies or surgical resections harbouring a CRA (without or with submucosal invasion) or overt colorectal carcinomas were challenged with p53 immunostaining. The largest section from single colorectal neoplasias was measured by the aid of a calibrated ocular scale in a conventional microscope. Lesions were divided into small adenomas (≤10 mm in size), large adenomas (≥11 mm in size), adenomas with submucosal invasion, and overt invasive carcinomas (without any recognizable adenoma remnant tissue).

RESULTS

CRAs with three or more dysplastic foci of p53-up-regulation gradually increased from 8% in small adenomas (size: ≤10 mm) to 48% in large adenomas (size: ≥11 mm), and to 65% in the adenomatous tissue in adenomas displaying submucosal invasion), but plummeted to 13% in the submucosal carcinomatous tissue and to 11% in overt carcinomas. In contrast, extensive p53 up-regulation predominated in the submucosal carcinomatous tissue (87%) and in overt carcinomas (89%).

CONCLUSION

The frequency of foci of dysplastic glands with up-regulation of p53 (hotspots) gradually increased from small to larger CRAs, being highest in the adenomatous tissue of CRAs with submucosal invasive carcinoma. The foci of p53 up-regulation became confluent (appreciated as extensive up-regulation) in the submucosal carcinomatous tissue and in overt carcinomas. It is concluded that a high number of foci with p53 up-regulation in adenomatous tissue might be required before submucosal invasive carcinoma ensues.

Distribution characteristics of colorectal polyps in 1990 cases of asymptomatic subjects

AIM: To investigate the prevalence of colorectal polyps in asymptomatic subjects to stress the importance of colonoscopy in physical examination and explore the effective means of screening for asymptomatic patients with early colorectal cancer.

METHODS: A retrospective analysis of colonoscopic findings was performed in 1990 subjects who underwent physical examination at the Department of Gastroenterology of Xinjiang Uygur Autonomous Region People's Hospital. The subjects voluntarily underwent colonoscopy from July 1, 2009 to June 30, 2013. The detection rate of colorectal polyps, pathological type, sex, age, site of lesion, and the positive rate of colorectal lesions were analyzed.

RESULTS: Colonoscopy revealed 376 (18.8%) cases of colorectal polyps, 10 (0.5%) cases of colorectal cancer, 410 (17.3%) cases of chronic colorectal inflammation, 38 (1.9%) cases of colon melanosis, 4 (0.2%) cases of colon melanosis with colon polyps, and 27 (1.3%) cases of colorectal diverticulum. A total of 571 polyps were detected in 376 patients with colorectal polyps. The detection rate of intestinal polyps was 24.1% in men and 11.2% in women. The detection rate of colorectal polyps in Chinese Han subjects was 17.8%. The detection rate of colorectal lesions was 39.1%.

CONCLUSION: The detection rate of colorectal polyps in the asymptomatic population was related to gender, age and race. The detection rate of colorectal polyps is higher in patients aged > 50 years. Sigmoid colon polyps and tubular adenoma are common. For people aged over 50 years, colonoscopy for screening early colorectal cancer is recommended.

Immunohistochemical Expression of ki-67 and p53 in Colorectal Adenomas: A Clinicopathological Study

OBJECTIVES

To evaluate the significance of P53 and Ki-67 expression as immunohistochemical markers in early detection of premalignant changes in different types of colorectal adenomas. Also, to correlate immunohistochemical expression of the two markers with different clinicopathological parameters including; age, and sex of the patient, type, site, size and grade of dysplasia of colorectal adenomas.

METHODS

Forty-seven polypectomy specimens of colorectal adenomas were retrieved from the archival materials of the Gastrointestinal and Hepatic Diseases Teaching Hospital in Baghdad from 2009 - 2010. Four µm section specimens were stained by immunohistochemical technique with Ki-67 and P53 tumor markers. P-values <0.05 were considered statistically significant.

RESULTS

Immunohistochemical expressions of Ki-67 and P53 had a significant correlation with the size and grade of dysplasia in colorectal adenomas. However, there was no significant correlation among the immunohistochemical expression of Ki-67 and P53 with the age and gender of the patient, and the type and site of colorectal adenomas. There was no significant correlation between Ki-67 and P53 expressions in colorectal adenomas. Villous adenomas of colorectum showed a significant correlation with the grade of dysplasia, while there was no significant correlation between size and site of colorectal adenoma with the grade of dysplasia.

CONCLUSION

High grade dysplasia with significant positive immunohistochemical markers of Ki-67 and P53 could be valuable parameters for selecting from the total colorectal adenoma population, those most deserving of close surveillance in follow-up cancer prevention programs. It is closely linked with increasing age particularly in patients with a large size adenoma of villous component in their histology.

Hepatocyte Paraffin 1 Immunoreactivity in Early Colon Carcinogenesis

Background

This study was aimed at evaluating the correlation between Hepatocyte paraffin 1 (Hep par 1) and colorectal cancer.

Methods

To this end, 50 intestinal biopsies were analyzed including 10 colorectal polyps with low grade dysplasia, 10 with high grade dysplasia, 10 colorectal adenocarcinomas, 10 specimens of normal ileum and 10 of normal colon mucosa. Tissue sections were immunostained for Hep par 1 utilizing a commercial antibody. Normal colonic mucosa did not express Hep par 1.

Results

Immunoreactivity for Hep par 1 was detected in 20% of polyps with low grade dysplasia, 50% of polyps with high grade dysplasia and 60% of colorectal carcinomas. Hep par 1 was frequently detected in the deepest areas of adenocarcinomas mainly in infiltrating tumour cells.

Conclusions

Our data show that Hep par 1 immunoreactivity in human colon carcinogenesis is correlated with progression from low grade to high grade dysplasia and adenocarcinoma. In clinical practice, our data show that caution should be taken in utilizing Hep par 1 as the sole tool in differentiating hepatocellular carcinoma from a liver metastasis of colon adenocarcinoma. Our data encourage further investigations into the potential role played by Hep par 1 in gastrointestinal carcinogenesis.

Heterogeneity of colorectal adenomas, the serrated adenoma, and implications for screening and surveillance

Current algorithms for screening and surveillance for colon cancer are valuable, but may be limited by the underlying nature of the targeted neoplastic lesions. Although part of the success of adenoma removal relates to interruption of so-called “adenoma-carcinoma sequence”, an alternate serrated pathway to colon cancer may pose difficulties with the ultimate results achieved by traditional colonoscopic methods. The endpoint carcinoma in this unique pathway may be derived from a dysplastic serrated adenoma. These tend to be located primarily in the right colon, especially in females, and are frequently associated with co-existent colon cancer. Unfortunately, however, there are few, if any, other identifiable risk factors, including age or family history of colon polyps or colon cancer. Moreover, this alternate serrated pathway may itself also be quite biologically heterogeneous as reflected in sessile serrated adenomas (SSA) with virtually exclusive molecular signatures defined by the presence of either BRAF or KRAS mutations. Screening algorithms in the future may need to be modified and individualized, depending on new information that likely will emerge on the natural history of these biologically heterogeneous lesions that differs from traditional adenomatous polyps.